I'm seeing a weird issue with a client where a lot of users are reporting missing folders in their Exchange mailboxes. Upon further investigation, it's found that the folders have been moved into other folders, and are easily recovered by just moving them back. It's tempting to diagnose as user error (who hasn't accidentally moved a folder at some point?), but it's been happening to an alarming number of people there lately.

Has anyone seen this? Or, failing that, have any idea where to start looking for a clue? My googling has so far turned up nothing that would explain this behaviour.

Thanks for your reply. I haven't heard any reports of file shares suffering the same behaviour, and I don't see how problems with the file system could cause this sort of weirdness in the Exchange store. I agree user error seems most likely, though it's a bit weird that so many users are affected so suddenly.